In this comprehensive review of retrospective childhood sexual abuse (CSA) instruments, instruments from studies published between 1986 and 2001 are examined according to administration method, number and specificity of questions, CSA operational definitions, psychometric properties, and the use of scales. It was found that both self-administered and interview instruments range from the vagueness of a single question to the preciseness of multiple, specific questions. Furthermore, the review demonstrated that CSA instruments generally lack standardization. Many are developed for onetime use and others modified when reused. Descriptive CSA instruments have been preferred by researchers and primarily used to measure CSA dichotomously. However, little consensus exists as to how to operationally define CSA. One positive trend is the development of scales that measure CSA as an interval-level variable, allowing for more extensive psychometric data to be collected.